Merge branch 'x86/bugs' into x86/core, to pick up pending changes before dependent...

[thirdparty/linux.git] / arch / x86 / kernel / cpu / amd.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/export.h>
#include <linux/bitops.h>
#include <linux/elf.h>
#include <linux/mm.h>

#include <linux/io.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <linux/random.h>
#include <linux/topology.h>
#include <asm/processor.h>
#include <asm/apic.h>
#include <asm/cacheinfo.h>
#include <asm/cpu.h>
#include <asm/spec-ctrl.h>
#include <asm/smp.h>
#include <asm/numa.h>
#include <asm/pci-direct.h>
#include <asm/delay.h>
#include <asm/debugreg.h>
#include <asm/resctrl.h>

#ifdef CONFIG_X86_64
# include <asm/mmconfig.h>
#endif

#include "cpu.h"

/*
 * nodes_per_socket: Stores the number of nodes per socket.
 * Refer to Fam15h Models 00-0fh BKDG - CPUID Fn8000_001E_ECX
 * Node Identifiers[10:8]
 */
static u32 nodes_per_socket = 1;

static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
{
        u32 gprs[8] = { 0 };
        int err;

        WARN_ONCE((boot_cpu_data.x86 != 0xf),
                  "%s should only be used on K8!\n", __func__);

        gprs[1] = msr;
        gprs[7] = 0x9c5a203a;

        err = rdmsr_safe_regs(gprs);

        *p = gprs[0] | ((u64)gprs[2] << 32);

        return err;
}

static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
{
        u32 gprs[8] = { 0 };

        WARN_ONCE((boot_cpu_data.x86 != 0xf),
                  "%s should only be used on K8!\n", __func__);

        gprs[0] = (u32)val;
        gprs[1] = msr;
        gprs[2] = val >> 32;
        gprs[7] = 0x9c5a203a;

        return wrmsr_safe_regs(gprs);
}

/*
 *      B step AMD K6 before B 9730xxxx have hardware bugs that can cause
 *      misexecution of code under Linux. Owners of such processors should
 *      contact AMD for precise details and a CPU swap.
 *
 *      See     http://www.multimania.com/poulot/k6bug.html
 *      and     section 2.6.2 of "AMD-K6 Processor Revision Guide - Model 6"
 *              (Publication # 21266  Issue Date: August 1998)
 *
 *      The following test is erm.. interesting. AMD neglected to up
 *      the chip setting when fixing the bug but they also tweaked some
 *      performance at the same time..
 */

#ifdef CONFIG_X86_32
extern __visible void vide(void);
__asm__(".text\n"
        ".globl vide\n"
        ".type vide, @function\n"
        ".align 4\n"
        "vide: ret\n");
#endif

static void init_amd_k5(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_32
/*
 * General Systems BIOSen alias the cpu frequency registers
 * of the Elan at 0x000df000. Unfortunately, one of the Linux
 * drivers subsequently pokes it, and changes the CPU speed.
 * Workaround : Remove the unneeded alias.
 */
#define CBAR            (0xfffc) /* Configuration Base Address  (32-bit) */
#define CBAR_ENB        (0x80000000)
#define CBAR_KEY        (0X000000CB)
        if (c->x86_model == 9 || c->x86_model == 10) {
                if (inl(CBAR) & CBAR_ENB)
                        outl(0 | CBAR_KEY, CBAR);
        }
#endif
}

static void init_amd_k6(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_32
        u32 l, h;
        int mbytes = get_num_physpages() >> (20-PAGE_SHIFT);

        if (c->x86_model < 6) {
                /* Based on AMD doc 20734R - June 2000 */
                if (c->x86_model == 0) {
                        clear_cpu_cap(c, X86_FEATURE_APIC);
                        set_cpu_cap(c, X86_FEATURE_PGE);
                }
                return;
        }

        if (c->x86_model == 6 && c->x86_stepping == 1) {
                const int K6_BUG_LOOP = 1000000;
                int n;
                void (*f_vide)(void);
                u64 d, d2;

                pr_info("AMD K6 stepping B detected - ");

                /*
                 * It looks like AMD fixed the 2.6.2 bug and improved indirect
                 * calls at the same time.
                 */

                n = K6_BUG_LOOP;
                f_vide = vide;
                OPTIMIZER_HIDE_VAR(f_vide);
                d = rdtsc();
                while (n--)
                        f_vide();
                d2 = rdtsc();
                d = d2-d;

                if (d > 20*K6_BUG_LOOP)
                        pr_cont("system stability may be impaired when more than 32 MB are used.\n");
                else
                        pr_cont("probably OK (after B9730xxxx).\n");
        }

        /* K6 with old style WHCR */
        if (c->x86_model < 8 ||
           (c->x86_model == 8 && c->x86_stepping < 8)) {
                /* We can only write allocate on the low 508Mb */
                if (mbytes > 508)
                        mbytes = 508;

                rdmsr(MSR_K6_WHCR, l, h);
                if ((l&0x0000FFFF) == 0) {
                        unsigned long flags;
                        l = (1<<0)|((mbytes/4)<<1);
                        local_irq_save(flags);
                        wbinvd();
                        wrmsr(MSR_K6_WHCR, l, h);
                        local_irq_restore(flags);
                        pr_info("Enabling old style K6 write allocation for %d Mb\n",
                                mbytes);
                }
                return;
        }

        if ((c->x86_model == 8 && c->x86_stepping > 7) ||
             c->x86_model == 9 || c->x86_model == 13) {
                /* The more serious chips .. */

                if (mbytes > 4092)
                        mbytes = 4092;

                rdmsr(MSR_K6_WHCR, l, h);
                if ((l&0xFFFF0000) == 0) {
                        unsigned long flags;
                        l = ((mbytes>>2)<<22)|(1<<16);
                        local_irq_save(flags);
                        wbinvd();
                        wrmsr(MSR_K6_WHCR, l, h);
                        local_irq_restore(flags);
                        pr_info("Enabling new style K6 write allocation for %d Mb\n",
                                mbytes);
                }

                return;
        }

        if (c->x86_model == 10) {
                /* AMD Geode LX is model 10 */
                /* placeholder for any needed mods */
                return;
        }
#endif
}

static void init_amd_k7(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_32
        u32 l, h;

        /*
         * Bit 15 of Athlon specific MSR 15, needs to be 0
         * to enable SSE on Palomino/Morgan/Barton CPU's.
         * If the BIOS didn't enable it already, enable it here.
         */
        if (c->x86_model >= 6 && c->x86_model <= 10) {
                if (!cpu_has(c, X86_FEATURE_XMM)) {
                        pr_info("Enabling disabled K7/SSE Support.\n");
                        msr_clear_bit(MSR_K7_HWCR, 15);
                        set_cpu_cap(c, X86_FEATURE_XMM);
                }
        }

        /*
         * It's been determined by AMD that Athlons since model 8 stepping 1
         * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
         * As per AMD technical note 27212 0.2
         */
        if ((c->x86_model == 8 && c->x86_stepping >= 1) || (c->x86_model > 8)) {
                rdmsr(MSR_K7_CLK_CTL, l, h);
                if ((l & 0xfff00000) != 0x20000000) {
                        pr_info("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
                                l, ((l & 0x000fffff)|0x20000000));
                        wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
                }
        }

        /* calling is from identify_secondary_cpu() ? */
        if (!c->cpu_index)
                return;

        /*
         * Certain Athlons might work (for various values of 'work') in SMP
         * but they are not certified as MP capable.
         */
        /* Athlon 660/661 is valid. */
        if ((c->x86_model == 6) && ((c->x86_stepping == 0) ||
            (c->x86_stepping == 1)))
                return;

        /* Duron 670 is valid */
        if ((c->x86_model == 7) && (c->x86_stepping == 0))
                return;

        /*
         * Athlon 662, Duron 671, and Athlon >model 7 have capability
         * bit. It's worth noting that the A5 stepping (662) of some
         * Athlon XP's have the MP bit set.
         * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
         * more.
         */
        if (((c->x86_model == 6) && (c->x86_stepping >= 2)) ||
            ((c->x86_model == 7) && (c->x86_stepping >= 1)) ||
             (c->x86_model > 7))
                if (cpu_has(c, X86_FEATURE_MP))
                        return;

        /* If we get here, not a certified SMP capable AMD system. */

        /*
         * Don't taint if we are running SMP kernel on a single non-MP
         * approved Athlon
         */
        WARN_ONCE(1, "WARNING: This combination of AMD"
                " processors is not suitable for SMP.\n");
        add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
#endif
}

#ifdef CONFIG_NUMA
/*
 * To workaround broken NUMA config.  Read the comment in
 * srat_detect_node().
 */
static int nearby_node(int apicid)
{
        int i, node;

        for (i = apicid - 1; i >= 0; i--) {
                node = __apicid_to_node[i];
                if (node != NUMA_NO_NODE && node_online(node))
                        return node;
        }
        for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
                node = __apicid_to_node[i];
                if (node != NUMA_NO_NODE && node_online(node))
                        return node;
        }
        return first_node(node_online_map); /* Shouldn't happen */
}
#endif

/*
 * Fix up topo::core_id for pre-F17h systems to be in the
 * [0 .. cores_per_node - 1] range. Not really needed but
 * kept so as not to break existing setups.
 */
static void legacy_fixup_core_id(struct cpuinfo_x86 *c)
{
        u32 cus_per_node;

        if (c->x86 >= 0x17)
                return;

        cus_per_node = c->x86_max_cores / nodes_per_socket;
        c->topo.core_id %= cus_per_node;
}

/*
 * Fixup core topology information for
 * (1) AMD multi-node processors
 *     Assumption: Number of cores in each internal node is the same.
 * (2) AMD processors supporting compute units
 */
static void amd_get_topology(struct cpuinfo_x86 *c)
{
        /* get information required for multi-node processors */
        if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
                int err;
                u32 eax, ebx, ecx, edx;

                cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);

                c->topo.die_id  = ecx & 0xff;

                if (c->x86 == 0x15)
                        c->topo.cu_id = ebx & 0xff;

                if (c->x86 >= 0x17) {
                        c->topo.core_id = ebx & 0xff;

                        if (smp_num_siblings > 1)
                                c->x86_max_cores /= smp_num_siblings;
                }

                /*
                 * In case leaf B is available, use it to derive
                 * topology information.
                 */
                err = detect_extended_topology(c);
                if (!err)
                        c->x86_coreid_bits = get_count_order(c->x86_max_cores);

                cacheinfo_amd_init_llc_id(c);

        } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
                u64 value;

                rdmsrl(MSR_FAM10H_NODE_ID, value);
                c->topo.die_id = value & 7;
                c->topo.llc_id = c->topo.die_id;
        } else
                return;

        if (nodes_per_socket > 1) {
                set_cpu_cap(c, X86_FEATURE_AMD_DCM);
                legacy_fixup_core_id(c);
        }
}

/*
 * On a AMD dual core setup the lower bits of the APIC id distinguish the cores.
 * Assumes number of cores is a power of two.
 */
static void amd_detect_cmp(struct cpuinfo_x86 *c)
{
        unsigned bits;

        bits = c->x86_coreid_bits;
        /* Low order bits define the core id (index of core in socket) */
        c->topo.core_id = c->topo.initial_apicid & ((1 << bits)-1);
        /* Convert the initial APIC ID into the socket ID */
        c->topo.pkg_id = c->topo.initial_apicid >> bits;
        /* use socket ID also for last level cache */
        c->topo.llc_id = c->topo.die_id = c->topo.pkg_id;
}

u32 amd_get_nodes_per_socket(void)
{
        return nodes_per_socket;
}
EXPORT_SYMBOL_GPL(amd_get_nodes_per_socket);

static void srat_detect_node(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_NUMA
        int cpu = smp_processor_id();
        int node;
        unsigned apicid = c->topo.apicid;

        node = numa_cpu_node(cpu);
        if (node == NUMA_NO_NODE)
                node = per_cpu_llc_id(cpu);

        /*
         * On multi-fabric platform (e.g. Numascale NumaChip) a
         * platform-specific handler needs to be called to fixup some
         * IDs of the CPU.
         */
        if (x86_cpuinit.fixup_cpu_id)
                x86_cpuinit.fixup_cpu_id(c, node);

        if (!node_online(node)) {
                /*
                 * Two possibilities here:
                 *
                 * - The CPU is missing memory and no node was created.  In
                 *   that case try picking one from a nearby CPU.
                 *
                 * - The APIC IDs differ from the HyperTransport node IDs
                 *   which the K8 northbridge parsing fills in.  Assume
                 *   they are all increased by a constant offset, but in
                 *   the same order as the HT nodeids.  If that doesn't
                 *   result in a usable node fall back to the path for the
                 *   previous case.
                 *
                 * This workaround operates directly on the mapping between
                 * APIC ID and NUMA node, assuming certain relationship
                 * between APIC ID, HT node ID and NUMA topology.  As going
                 * through CPU mapping may alter the outcome, directly
                 * access __apicid_to_node[].
                 */
                int ht_nodeid = c->topo.initial_apicid;

                if (__apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
                        node = __apicid_to_node[ht_nodeid];
                /* Pick a nearby node */
                if (!node_online(node))
                        node = nearby_node(apicid);
        }
        numa_set_node(cpu, node);
#endif
}

static void early_init_amd_mc(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
        unsigned bits, ecx;

        /* Multi core CPU? */
        if (c->extended_cpuid_level < 0x80000008)
                return;

        ecx = cpuid_ecx(0x80000008);

        c->x86_max_cores = (ecx & 0xff) + 1;

        /* CPU telling us the core id bits shift? */
        bits = (ecx >> 12) & 0xF;

        /* Otherwise recompute */
        if (bits == 0) {
                while ((1 << bits) < c->x86_max_cores)
                        bits++;
        }

        c->x86_coreid_bits = bits;
#endif
}

static void bsp_init_amd(struct cpuinfo_x86 *c)
{
        if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {

                if (c->x86 > 0x10 ||
                    (c->x86 == 0x10 && c->x86_model >= 0x2)) {
                        u64 val;

                        rdmsrl(MSR_K7_HWCR, val);
                        if (!(val & BIT(24)))
                                pr_warn(FW_BUG "TSC doesn't count with P0 frequency!\n");
                }
        }

        if (c->x86 == 0x15) {
                unsigned long upperbit;
                u32 cpuid, assoc;

                cpuid    = cpuid_edx(0x80000005);
                assoc    = cpuid >> 16 & 0xff;
                upperbit = ((cpuid >> 24) << 10) / assoc;

                va_align.mask     = (upperbit - 1) & PAGE_MASK;
                va_align.flags    = ALIGN_VA_32 | ALIGN_VA_64;

                /* A random value per boot for bit slice [12:upper_bit) */
                va_align.bits = get_random_u32() & va_align.mask;
        }

        if (cpu_has(c, X86_FEATURE_MWAITX))
                use_mwaitx_delay();

        if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
                u32 ecx;

                ecx = cpuid_ecx(0x8000001e);
                __max_die_per_package = nodes_per_socket = ((ecx >> 8) & 7) + 1;
        } else if (boot_cpu_has(X86_FEATURE_NODEID_MSR)) {
                u64 value;

                rdmsrl(MSR_FAM10H_NODE_ID, value);
                __max_die_per_package = nodes_per_socket = ((value >> 3) & 7) + 1;
        }

        if (!boot_cpu_has(X86_FEATURE_AMD_SSBD) &&
            !boot_cpu_has(X86_FEATURE_VIRT_SSBD) &&
            c->x86 >= 0x15 && c->x86 <= 0x17) {
                unsigned int bit;

                switch (c->x86) {
                case 0x15: bit = 54; break;
                case 0x16: bit = 33; break;
                case 0x17: bit = 10; break;
                default: return;
                }
                /*
                 * Try to cache the base value so further operations can
                 * avoid RMW. If that faults, do not enable SSBD.
                 */
                if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &x86_amd_ls_cfg_base)) {
                        setup_force_cpu_cap(X86_FEATURE_LS_CFG_SSBD);
                        setup_force_cpu_cap(X86_FEATURE_SSBD);
                        x86_amd_ls_cfg_ssbd_mask = 1ULL << bit;
                }
        }

        resctrl_cpu_detect(c);

        /* Figure out Zen generations: */
        switch (c->x86) {
        case 0x17:
                switch (c->x86_model) {
                case 0x00 ... 0x2f:
                case 0x50 ... 0x5f:
                        setup_force_cpu_cap(X86_FEATURE_ZEN1);
                        break;
                case 0x30 ... 0x4f:
                case 0x60 ... 0x7f:
                case 0x90 ... 0x91:
                case 0xa0 ... 0xaf:
                        setup_force_cpu_cap(X86_FEATURE_ZEN2);
                        break;
                default:
                        goto warn;
                }
                break;

        case 0x19:
                switch (c->x86_model) {
                case 0x00 ... 0x0f:
                case 0x20 ... 0x5f:
                        setup_force_cpu_cap(X86_FEATURE_ZEN3);
                        break;
                case 0x10 ... 0x1f:
                case 0x60 ... 0xaf:
                        setup_force_cpu_cap(X86_FEATURE_ZEN4);
                        break;
                default:
                        goto warn;
                }
                break;

        case 0x1a:
                switch (c->x86_model) {
                case 0x00 ... 0x0f:
                case 0x20 ... 0x2f:
                case 0x40 ... 0x4f:
                case 0x70 ... 0x7f:
                        setup_force_cpu_cap(X86_FEATURE_ZEN5);
                        break;
                default:
                        goto warn;
                }
                break;

        default:
                break;
        }

        return;

warn:
        WARN_ONCE(1, "Family 0x%x, model: 0x%x??\n", c->x86, c->x86_model);
}

static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
{
        u64 msr;

        /*
         * BIOS support is required for SME and SEV.
         *   For SME: If BIOS has enabled SME then adjust x86_phys_bits by
         *            the SME physical address space reduction value.
         *            If BIOS has not enabled SME then don't advertise the
         *            SME feature (set in scattered.c).
         *            If the kernel has not enabled SME via any means then
         *            don't advertise the SME feature.
         *   For SEV: If BIOS has not enabled SEV then don't advertise the
         *            SEV and SEV_ES feature (set in scattered.c).
         *
         *   In all cases, since support for SME and SEV requires long mode,
         *   don't advertise the feature under CONFIG_X86_32.
         */
        if (cpu_has(c, X86_FEATURE_SME) || cpu_has(c, X86_FEATURE_SEV)) {
                /* Check if memory encryption is enabled */
                rdmsrl(MSR_AMD64_SYSCFG, msr);
                if (!(msr & MSR_AMD64_SYSCFG_MEM_ENCRYPT))
                        goto clear_all;

                /*
                 * Always adjust physical address bits. Even though this
                 * will be a value above 32-bits this is still done for
                 * CONFIG_X86_32 so that accurate values are reported.
                 */
                c->x86_phys_bits -= (cpuid_ebx(0x8000001f) >> 6) & 0x3f;

                if (IS_ENABLED(CONFIG_X86_32))
                        goto clear_all;

                if (!sme_me_mask)
                        setup_clear_cpu_cap(X86_FEATURE_SME);

                rdmsrl(MSR_K7_HWCR, msr);
                if (!(msr & MSR_K7_HWCR_SMMLOCK))
                        goto clear_sev;

                return;

clear_all:
                setup_clear_cpu_cap(X86_FEATURE_SME);
clear_sev:
                setup_clear_cpu_cap(X86_FEATURE_SEV);
                setup_clear_cpu_cap(X86_FEATURE_SEV_ES);
        }
}

static void early_init_amd(struct cpuinfo_x86 *c)
{
        u64 value;
        u32 dummy;

        early_init_amd_mc(c);

        if (c->x86 >= 0xf)
                set_cpu_cap(c, X86_FEATURE_K8);

        rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);

        /*
         * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
         * with P/T states and does not stop in deep C-states
         */
        if (c->x86_power & (1 << 8)) {
                set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
                set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
        }

        /* Bit 12 of 8000_0007 edx is accumulated power mechanism. */
        if (c->x86_power & BIT(12))
                set_cpu_cap(c, X86_FEATURE_ACC_POWER);

        /* Bit 14 indicates the Runtime Average Power Limit interface. */
        if (c->x86_power & BIT(14))
                set_cpu_cap(c, X86_FEATURE_RAPL);

#ifdef CONFIG_X86_64
        set_cpu_cap(c, X86_FEATURE_SYSCALL32);
#else
        /*  Set MTRR capability flag if appropriate */
        if (c->x86 == 5)
                if (c->x86_model == 13 || c->x86_model == 9 ||
                    (c->x86_model == 8 && c->x86_stepping >= 8))
                        set_cpu_cap(c, X86_FEATURE_K6_MTRR);
#endif
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
        /*
         * ApicID can always be treated as an 8-bit value for AMD APIC versions
         * >= 0x10, but even old K8s came out of reset with version 0x10. So, we
         * can safely set X86_FEATURE_EXTD_APICID unconditionally for families
         * after 16h.
         */
        if (boot_cpu_has(X86_FEATURE_APIC)) {
                if (c->x86 > 0x16)
                        set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
                else if (c->x86 >= 0xf) {
                        /* check CPU config space for extended APIC ID */
                        unsigned int val;

                        val = read_pci_config(0, 24, 0, 0x68);
                        if ((val >> 17 & 0x3) == 0x3)
                                set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
                }
        }
#endif

        /*
         * This is only needed to tell the kernel whether to use VMCALL
         * and VMMCALL.  VMMCALL is never executed except under virt, so
         * we can set it unconditionally.
         */
        set_cpu_cap(c, X86_FEATURE_VMMCALL);

        /* F16h erratum 793, CVE-2013-6885 */
        if (c->x86 == 0x16 && c->x86_model <= 0xf)
                msr_set_bit(MSR_AMD64_LS_CFG, 15);

        early_detect_mem_encrypt(c);

        /* Re-enable TopologyExtensions if switched off by BIOS */
        if (c->x86 == 0x15 &&
            (c->x86_model >= 0x10 && c->x86_model <= 0x6f) &&
            !cpu_has(c, X86_FEATURE_TOPOEXT)) {

                if (msr_set_bit(0xc0011005, 54) > 0) {
                        rdmsrl(0xc0011005, value);
                        if (value & BIT_64(54)) {
                                set_cpu_cap(c, X86_FEATURE_TOPOEXT);
                                pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
                        }
                }
        }

        if (cpu_has(c, X86_FEATURE_TOPOEXT))
                smp_num_siblings = ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1;

        if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && !cpu_has(c, X86_FEATURE_IBPB_BRTYPE)) {
                if (c->x86 == 0x17 && boot_cpu_has(X86_FEATURE_AMD_IBPB))
                        setup_force_cpu_cap(X86_FEATURE_IBPB_BRTYPE);
                else if (c->x86 >= 0x19 && !wrmsrl_safe(MSR_IA32_PRED_CMD, PRED_CMD_SBPB)) {
                        setup_force_cpu_cap(X86_FEATURE_IBPB_BRTYPE);
                        setup_force_cpu_cap(X86_FEATURE_SBPB);
                }
        }
}

static void init_amd_k8(struct cpuinfo_x86 *c)
{
        u32 level;
        u64 value;

        /* On C+ stepping K8 rep microcode works well for copy/memset */
        level = cpuid_eax(1);
        if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
                set_cpu_cap(c, X86_FEATURE_REP_GOOD);

        /*
         * Some BIOSes incorrectly force this feature, but only K8 revision D
         * (model = 0x14) and later actually support it.
         * (AMD Erratum #110, docId: 25759).
         */
        if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
                clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
                if (!rdmsrl_amd_safe(0xc001100d, &value)) {
                        value &= ~BIT_64(32);
                        wrmsrl_amd_safe(0xc001100d, value);
                }
        }

        if (!c->x86_model_id[0])
                strcpy(c->x86_model_id, "Hammer");

#ifdef CONFIG_SMP
        /*
         * Disable TLB flush filter by setting HWCR.FFDIS on K8
         * bit 6 of msr C001_0015
         *
         * Errata 63 for SH-B3 steppings
         * Errata 122 for all steppings (F+ have it disabled by default)
         */
        msr_set_bit(MSR_K7_HWCR, 6);
#endif
        set_cpu_bug(c, X86_BUG_SWAPGS_FENCE);

        /*
         * Check models and steppings affected by erratum 400. This is
         * used to select the proper idle routine and to enable the
         * check whether the machine is affected in arch_post_acpi_subsys_init()
         * which sets the X86_BUG_AMD_APIC_C1E bug depending on the MSR check.
         */
        if (c->x86_model > 0x41 ||
            (c->x86_model == 0x41 && c->x86_stepping >= 0x2))
                setup_force_cpu_bug(X86_BUG_AMD_E400);
}

static void init_amd_gh(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_MMCONF_FAM10H
        /* do this for boot cpu */
        if (c == &boot_cpu_data)
                check_enable_amd_mmconf_dmi();

        fam10h_check_enable_mmcfg();
#endif

        /*
         * Disable GART TLB Walk Errors on Fam10h. We do this here because this
         * is always needed when GART is enabled, even in a kernel which has no
         * MCE support built in. BIOS should disable GartTlbWlk Errors already.
         * If it doesn't, we do it here as suggested by the BKDG.
         *
         * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
         */
        msr_set_bit(MSR_AMD64_MCx_MASK(4), 10);

        /*
         * On family 10h BIOS may not have properly enabled WC+ support, causing
         * it to be converted to CD memtype. This may result in performance
         * degradation for certain nested-paging guests. Prevent this conversion
         * by clearing bit 24 in MSR_AMD64_BU_CFG2.
         *
         * NOTE: we want to use the _safe accessors so as not to #GP kvm
         * guests on older kvm hosts.
         */
        msr_clear_bit(MSR_AMD64_BU_CFG2, 24);

        set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);

        /*
         * Check models and steppings affected by erratum 400. This is
         * used to select the proper idle routine and to enable the
         * check whether the machine is affected in arch_post_acpi_subsys_init()
         * which sets the X86_BUG_AMD_APIC_C1E bug depending on the MSR check.
         */
        if (c->x86_model > 0x2 ||
            (c->x86_model == 0x2 && c->x86_stepping >= 0x1))
                setup_force_cpu_bug(X86_BUG_AMD_E400);
}

static void init_amd_ln(struct cpuinfo_x86 *c)
{
        /*
         * Apply erratum 665 fix unconditionally so machines without a BIOS
         * fix work.
         */
        msr_set_bit(MSR_AMD64_DE_CFG, 31);
}

static bool rdrand_force;

static int __init rdrand_cmdline(char *str)
{
        if (!str)
                return -EINVAL;

        if (!strcmp(str, "force"))
                rdrand_force = true;
        else
                return -EINVAL;

        return 0;
}
early_param("rdrand", rdrand_cmdline);

static void clear_rdrand_cpuid_bit(struct cpuinfo_x86 *c)
{
        /*
         * Saving of the MSR used to hide the RDRAND support during
         * suspend/resume is done by arch/x86/power/cpu.c, which is
         * dependent on CONFIG_PM_SLEEP.
         */
        if (!IS_ENABLED(CONFIG_PM_SLEEP))
                return;

        /*
         * The self-test can clear X86_FEATURE_RDRAND, so check for
         * RDRAND support using the CPUID function directly.
         */
        if (!(cpuid_ecx(1) & BIT(30)) || rdrand_force)
                return;

        msr_clear_bit(MSR_AMD64_CPUID_FN_1, 62);

        /*
         * Verify that the CPUID change has occurred in case the kernel is
         * running virtualized and the hypervisor doesn't support the MSR.
         */
        if (cpuid_ecx(1) & BIT(30)) {
                pr_info_once("BIOS may not properly restore RDRAND after suspend, but hypervisor does not support hiding RDRAND via CPUID.\n");
                return;
        }

        clear_cpu_cap(c, X86_FEATURE_RDRAND);
        pr_info_once("BIOS may not properly restore RDRAND after suspend, hiding RDRAND via CPUID. Use rdrand=force to reenable.\n");
}

static void init_amd_jg(struct cpuinfo_x86 *c)
{
        /*
         * Some BIOS implementations do not restore proper RDRAND support
         * across suspend and resume. Check on whether to hide the RDRAND
         * instruction support via CPUID.
         */
        clear_rdrand_cpuid_bit(c);
}

static void init_amd_bd(struct cpuinfo_x86 *c)
{
        u64 value;

        /*
         * The way access filter has a performance penalty on some workloads.
         * Disable it on the affected CPUs.
         */
        if ((c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
                if (!rdmsrl_safe(MSR_F15H_IC_CFG, &value) && !(value & 0x1E)) {
                        value |= 0x1E;
                        wrmsrl_safe(MSR_F15H_IC_CFG, value);
                }
        }

        /*
         * Some BIOS implementations do not restore proper RDRAND support
         * across suspend and resume. Check on whether to hide the RDRAND
         * instruction support via CPUID.
         */
        clear_rdrand_cpuid_bit(c);
}

static void fix_erratum_1386(struct cpuinfo_x86 *c)
{
        /*
         * Work around Erratum 1386.  The XSAVES instruction malfunctions in
         * certain circumstances on Zen1/2 uarch, and not all parts have had
         * updated microcode at the time of writing (March 2023).
         *
         * Affected parts all have no supervisor XSAVE states, meaning that
         * the XSAVEC instruction (which works fine) is equivalent.
         */
        clear_cpu_cap(c, X86_FEATURE_XSAVES);
}

void init_spectral_chicken(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_MITIGATION_UNRET_ENTRY
        u64 value;

        /*
         * On Zen2 we offer this chicken (bit) on the altar of Speculation.
         *
         * This suppresses speculation from the middle of a basic block, i.e. it
         * suppresses non-branch predictions.
         */
        if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) {
                if (!rdmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, &value)) {
                        value |= MSR_ZEN2_SPECTRAL_CHICKEN_BIT;
                        wrmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, value);
                }
        }
#endif
}

static void init_amd_zen_common(void)
{
        setup_force_cpu_cap(X86_FEATURE_ZEN);
#ifdef CONFIG_NUMA
        node_reclaim_distance = 32;
#endif
}

static void init_amd_zen1(struct cpuinfo_x86 *c)
{
        init_amd_zen_common();
        fix_erratum_1386(c);

        /* Fix up CPUID bits, but only if not virtualised. */
        if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) {

                /* Erratum 1076: CPB feature bit not being set in CPUID. */
                if (!cpu_has(c, X86_FEATURE_CPB))
                        set_cpu_cap(c, X86_FEATURE_CPB);
        }

        pr_notice_once("AMD Zen1 DIV0 bug detected. Disable SMT for full protection.\n");
        setup_force_cpu_bug(X86_BUG_DIV0);
}

static bool cpu_has_zenbleed_microcode(void)
{
        u32 good_rev = 0;

        switch (boot_cpu_data.x86_model) {
        case 0x30 ... 0x3f: good_rev = 0x0830107a; break;
        case 0x60 ... 0x67: good_rev = 0x0860010b; break;
        case 0x68 ... 0x6f: good_rev = 0x08608105; break;
        case 0x70 ... 0x7f: good_rev = 0x08701032; break;
        case 0xa0 ... 0xaf: good_rev = 0x08a00008; break;

        default:
                return false;
        }

        if (boot_cpu_data.microcode < good_rev)
                return false;

        return true;
}

static void zen2_zenbleed_check(struct cpuinfo_x86 *c)
{
        if (cpu_has(c, X86_FEATURE_HYPERVISOR))
                return;

        if (!cpu_has(c, X86_FEATURE_AVX))
                return;

        if (!cpu_has_zenbleed_microcode()) {
                pr_notice_once("Zenbleed: please update your microcode for the most optimal fix\n");
                msr_set_bit(MSR_AMD64_DE_CFG, MSR_AMD64_DE_CFG_ZEN2_FP_BACKUP_FIX_BIT);
        } else {
                msr_clear_bit(MSR_AMD64_DE_CFG, MSR_AMD64_DE_CFG_ZEN2_FP_BACKUP_FIX_BIT);
        }
}

static void init_amd_zen2(struct cpuinfo_x86 *c)
{
        init_amd_zen_common();
        init_spectral_chicken(c);
        fix_erratum_1386(c);
        zen2_zenbleed_check(c);
}

static void init_amd_zen3(struct cpuinfo_x86 *c)
{
        init_amd_zen_common();

        if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) {
                /*
                 * Zen3 (Fam19 model < 0x10) parts are not susceptible to
                 * Branch Type Confusion, but predate the allocation of the
                 * BTC_NO bit.
                 */
                if (!cpu_has(c, X86_FEATURE_BTC_NO))
                        set_cpu_cap(c, X86_FEATURE_BTC_NO);
        }
}

static void init_amd_zen4(struct cpuinfo_x86 *c)
{
        init_amd_zen_common();

        if (!cpu_has(c, X86_FEATURE_HYPERVISOR))
                msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT);
}

static void init_amd_zen5(struct cpuinfo_x86 *c)
{
        init_amd_zen_common();
}

static void init_amd(struct cpuinfo_x86 *c)
{
        u64 vm_cr;

        early_init_amd(c);

        /*
         * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
         * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
         */
        clear_cpu_cap(c, 0*32+31);

        if (c->x86 >= 0x10)
                set_cpu_cap(c, X86_FEATURE_REP_GOOD);

        /* AMD FSRM also implies FSRS */
        if (cpu_has(c, X86_FEATURE_FSRM))
                set_cpu_cap(c, X86_FEATURE_FSRS);

        /* get apicid instead of initial apic id from cpuid */
        c->topo.apicid = read_apic_id();

        /* K6s reports MCEs but don't actually have all the MSRs */
        if (c->x86 < 6)
                clear_cpu_cap(c, X86_FEATURE_MCE);

        switch (c->x86) {
        case 4:    init_amd_k5(c); break;
        case 5:    init_amd_k6(c); break;
        case 6:    init_amd_k7(c); break;
        case 0xf:  init_amd_k8(c); break;
        case 0x10: init_amd_gh(c); break;
        case 0x12: init_amd_ln(c); break;
        case 0x15: init_amd_bd(c); break;
        case 0x16: init_amd_jg(c); break;
        }

        if (boot_cpu_has(X86_FEATURE_ZEN1))
                init_amd_zen1(c);
        else if (boot_cpu_has(X86_FEATURE_ZEN2))
                init_amd_zen2(c);
        else if (boot_cpu_has(X86_FEATURE_ZEN3))
                init_amd_zen3(c);
        else if (boot_cpu_has(X86_FEATURE_ZEN4))
                init_amd_zen4(c);
        else if (boot_cpu_has(X86_FEATURE_ZEN5))
                init_amd_zen5(c);

        /*
         * Enable workaround for FXSAVE leak on CPUs
         * without a XSaveErPtr feature
         */
        if ((c->x86 >= 6) && (!cpu_has(c, X86_FEATURE_XSAVEERPTR)))
                set_cpu_bug(c, X86_BUG_FXSAVE_LEAK);

        cpu_detect_cache_sizes(c);

        amd_detect_cmp(c);
        amd_get_topology(c);
        srat_detect_node(c);

        init_amd_cacheinfo(c);

        if (cpu_has(c, X86_FEATURE_SVM)) {
                rdmsrl(MSR_VM_CR, vm_cr);
                if (vm_cr & SVM_VM_CR_SVM_DIS_MASK) {
                        pr_notice_once("SVM disabled (by BIOS) in MSR_VM_CR\n");
                        clear_cpu_cap(c, X86_FEATURE_SVM);
                }
        }

        if (!cpu_has(c, X86_FEATURE_LFENCE_RDTSC) && cpu_has(c, X86_FEATURE_XMM2)) {
                /*
                 * Use LFENCE for execution serialization.  On families which
                 * don't have that MSR, LFENCE is already serializing.
                 * msr_set_bit() uses the safe accessors, too, even if the MSR
                 * is not present.
                 */
                msr_set_bit(MSR_AMD64_DE_CFG,
                            MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT);

                /* A serializing LFENCE stops RDTSC speculation */
                set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
        }

        /*
         * Family 0x12 and above processors have APIC timer
         * running in deep C states.
         */
        if (c->x86 > 0x11)
                set_cpu_cap(c, X86_FEATURE_ARAT);

        /* 3DNow or LM implies PREFETCHW */
        if (!cpu_has(c, X86_FEATURE_3DNOWPREFETCH))
                if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
                        set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);

        /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
        if (!cpu_feature_enabled(X86_FEATURE_XENPV))
                set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);

        /*
         * Turn on the Instructions Retired free counter on machines not
         * susceptible to erratum #1054 "Instructions Retired Performance
         * Counter May Be Inaccurate".
         */
        if (cpu_has(c, X86_FEATURE_IRPERF) &&
            (boot_cpu_has(X86_FEATURE_ZEN1) && c->x86_model > 0x2f))
                msr_set_bit(MSR_K7_HWCR, MSR_K7_HWCR_IRPERF_EN_BIT);

        check_null_seg_clears_base(c);

        /*
         * Make sure EFER[AIBRSE - Automatic IBRS Enable] is set. The APs are brought up
         * using the trampoline code and as part of it, MSR_EFER gets prepared there in
         * order to be replicated onto them. Regardless, set it here again, if not set,
         * to protect against any future refactoring/code reorganization which might
         * miss setting this important bit.
         */
        if (spectre_v2_in_eibrs_mode(spectre_v2_enabled) &&
            cpu_has(c, X86_FEATURE_AUTOIBRS))
                WARN_ON_ONCE(msr_set_bit(MSR_EFER, _EFER_AUTOIBRS));

        /* AMD CPUs don't need fencing after x2APIC/TSC_DEADLINE MSR writes. */
        clear_cpu_cap(c, X86_FEATURE_APIC_MSRS_FENCE);
}

#ifdef CONFIG_X86_32
static unsigned int amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
{
        /* AMD errata T13 (order #21922) */
        if (c->x86 == 6) {
                /* Duron Rev A0 */
                if (c->x86_model == 3 && c->x86_stepping == 0)
                        size = 64;
                /* Tbird rev A1/A2 */
                if (c->x86_model == 4 &&
                        (c->x86_stepping == 0 || c->x86_stepping == 1))
                        size = 256;
        }
        return size;
}
#endif

static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
{
        u32 ebx, eax, ecx, edx;
        u16 mask = 0xfff;

        if (c->x86 < 0xf)
                return;

        if (c->extended_cpuid_level < 0x80000006)
                return;

        cpuid(0x80000006, &eax, &ebx, &ecx, &edx);

        tlb_lld_4k[ENTRIES] = (ebx >> 16) & mask;
        tlb_lli_4k[ENTRIES] = ebx & mask;

        /*
         * K8 doesn't have 2M/4M entries in the L2 TLB so read out the L1 TLB
         * characteristics from the CPUID function 0x80000005 instead.
         */
        if (c->x86 == 0xf) {
                cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
                mask = 0xff;
        }

        /* Handle DTLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
        if (!((eax >> 16) & mask))
                tlb_lld_2m[ENTRIES] = (cpuid_eax(0x80000005) >> 16) & 0xff;
        else
                tlb_lld_2m[ENTRIES] = (eax >> 16) & mask;

        /* a 4M entry uses two 2M entries */
        tlb_lld_4m[ENTRIES] = tlb_lld_2m[ENTRIES] >> 1;

        /* Handle ITLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
        if (!(eax & mask)) {
                /* Erratum 658 */
                if (c->x86 == 0x15 && c->x86_model <= 0x1f) {
                        tlb_lli_2m[ENTRIES] = 1024;
                } else {
                        cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
                        tlb_lli_2m[ENTRIES] = eax & 0xff;
                }
        } else
                tlb_lli_2m[ENTRIES] = eax & mask;

        tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
}

static const struct cpu_dev amd_cpu_dev = {
        .c_vendor       = "AMD",
        .c_ident        = { "AuthenticAMD" },
#ifdef CONFIG_X86_32
        .legacy_models = {
                { .family = 4, .model_names =
                  {
                          [3] = "486 DX/2",
                          [7] = "486 DX/2-WB",
                          [8] = "486 DX/4",
                          [9] = "486 DX/4-WB",
                          [14] = "Am5x86-WT",
                          [15] = "Am5x86-WB"
                  }
                },
        },
        .legacy_cache_size = amd_size_cache,
#endif
        .c_early_init   = early_init_amd,
        .c_detect_tlb   = cpu_detect_tlb_amd,
        .c_bsp_init     = bsp_init_amd,
        .c_init         = init_amd,
        .c_x86_vendor   = X86_VENDOR_AMD,
};

cpu_dev_register(amd_cpu_dev);

static DEFINE_PER_CPU_READ_MOSTLY(unsigned long[4], amd_dr_addr_mask);

static unsigned int amd_msr_dr_addr_masks[] = {
        MSR_F16H_DR0_ADDR_MASK,
        MSR_F16H_DR1_ADDR_MASK,
        MSR_F16H_DR1_ADDR_MASK + 1,
        MSR_F16H_DR1_ADDR_MASK + 2
};

void amd_set_dr_addr_mask(unsigned long mask, unsigned int dr)
{
        int cpu = smp_processor_id();

        if (!cpu_feature_enabled(X86_FEATURE_BPEXT))
                return;

        if (WARN_ON_ONCE(dr >= ARRAY_SIZE(amd_msr_dr_addr_masks)))
                return;

        if (per_cpu(amd_dr_addr_mask, cpu)[dr] == mask)
                return;

        wrmsr(amd_msr_dr_addr_masks[dr], mask, 0);
        per_cpu(amd_dr_addr_mask, cpu)[dr] = mask;
}

unsigned long amd_get_dr_addr_mask(unsigned int dr)
{
        if (!cpu_feature_enabled(X86_FEATURE_BPEXT))
                return 0;

        if (WARN_ON_ONCE(dr >= ARRAY_SIZE(amd_msr_dr_addr_masks)))
                return 0;

        return per_cpu(amd_dr_addr_mask[dr], smp_processor_id());
}
EXPORT_SYMBOL_GPL(amd_get_dr_addr_mask);

u32 amd_get_highest_perf(void)
{
        struct cpuinfo_x86 *c = &boot_cpu_data;

        if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
                               (c->x86_model >= 0x70 && c->x86_model < 0x80)))
                return 166;

        if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
                               (c->x86_model >= 0x40 && c->x86_model < 0x70)))
                return 166;

        return 255;
}
EXPORT_SYMBOL_GPL(amd_get_highest_perf);

static void zenbleed_check_cpu(void *unused)
{
        struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());

        zen2_zenbleed_check(c);
}

void amd_check_microcode(void)
{
        if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
                return;

        on_each_cpu(zenbleed_check_cpu, NULL, 1);
}

/*
 * Issue a DIV 0/1 insn to clear any division data from previous DIV
 * operations.
 */
void noinstr amd_clear_divider(void)
{
        asm volatile(ALTERNATIVE("", "div %2\n\t", X86_BUG_DIV0)
                     :: "a" (0), "d" (0), "r" (1));
}
EXPORT_SYMBOL_GPL(amd_clear_divider);